Distance estimation device, antenna device, feed system, feed device, and feed method

Abstract

A distance estimation device estimates a distance between an image acquiring unit and a marker in a first axis direction, based on coordinates of an upper end portion of the marker; coordinates of a lower end portion of the marker; and a length between the upper end portion and the lower end portion. The distance estimation device estimates a distance between the image acquiring unit and the marker in a third axis direction, based on a first elevation angle of a projected position and the distance in the first axis direction.

The invention claimed is: 
     
         1 . A distance estimation device comprising:
 an image acquiring device configured to acquire an image through a fisheye lens; and   circuitry configured to:
 convert a first position of a marker that is included in the acquired image, into a second position of polar coordinates on a first plane that includes a first axis and a second axis, the first position being used in the image acquiring device; 
 acquire, based on the second position, a first elevation angle of a projected position that is obtained by projecting the first position onto a second plane including the first axis and a third axis, the first elevation angle being relative to the third axis of the second plane; and 
 estimate distances between the image acquiring device and the marker, 
   wherein the circuitry is configured to:
 estimate a distance between the image acquiring device and the marker in a first axis direction, based on
 coordinates of an upper end portion of the marker, the coordinates being determined based on a second elevation angle and an azimuth angle of the upper end portion of the marker included in the image, the second elevation angle being relative to the third axis, and the azimuth angle being relative to the first axis, 
 coordinates of a lower end portion of the marker, the coordinates of the lower end portion being determined based on a third elevation angle and an azimuth angle of the lower end portion of the marker included in the image, the third elevation angle being relative to the third axis, and the azimuth angle of the lower end portion being relative to the first axis, and 
 a length between the upper end portion and the lower end portion, 
 
 estimate a distance between the image acquiring device and the marker in a third axis direction, based on the acquired first elevation angle and the estimated distance in the first axis direction. 
   
     
     
         2 . The distance estimation device according to  claim 1 , wherein upon occurrence of a condition in which the first elevation angle is not in a predetermined angle range including zero degrees, the circuitry is configured to
 estimate the distance between the image acquiring device and the marker in the first axis direction, and   estimate the distance between the image acquiring device and the marker in the third axis direction, based on the first elevation angle and the estimated distance in the first axis direction.   
     
     
         3 . The distance estimation device according to  claim 2 , wherein upon occurrence of a condition in which the first elevation angle is in the predetermined angle range including zero degrees, the circuitry is configured to estimate the distance between the image acquiring device and the marker in the third axis direction, based on the image. 
     
     
         4 . The distance estimation device according to  claim 3 , wherein the circuitry is configured to detect a positional deviation between the image acquiring device and the marker in a second axis direction, based on a position of a center of gravity of the marker included in the image,
 wherein upon occurrence of the condition in which the first elevation angle is in the predetermined angle range including zero degrees, the circuitry is configured to estimate the distance between the image acquiring device and the marker, based on the image that is obtained by making a correction in accordance with an extent to which the positional deviation is detected by the circuitry.   
     
     
         5 . The distance estimation device according to  claim 1 , wherein the upper end portion and the lower end portion are an upper end and a lower end of the marker, respectively. 
     
     
         6 . The distance estimation device according to  claim 1 , wherein the circuitry is configured to determine, as the first elevation angle, a value that is obtained by dividing coordinates of a mapped position by a focal length of the fisheye lens, the mapped position being obtained by mapping the second position onto the first axis. 
     
     
         7 . The distance estimation device according to  claim 6 , wherein the coordinates of the mapped position are indicated by a value that is obtained by multiplying a radius vector used for the polar coordinates by a cosine of an argument. 
     
     
         8 . An antenna device comprising:
 the distance estimation device according to  claim 1 ;   an array antenna including multiple antenna elements that are bidimensionally arranged along the first axis and the second axis;   a phase adjuster configured to adjust phases of transmission power signals that are respectively supplied by the multiple antenna elements, with respect to the first axis direction; and   a control circuit configured to control the phase adjuster based on the first elevation angle and the distance in the third axis direction.   
     
     
         9 . The antenna device according to  claim 8 , wherein the multiple antenna elements are grouped into multiple subarrays each of which extends along the second axis direction, and
 wherein the phase adjuster includes multiple phase shifters coupled to the respective subarrays and configured to adjust the phases of the transmission power signals for the respective subarrays.   
     
     
         10 . The antenna device according to  claim 8 , further comprising:
 a storage that stores length data indicating a length between the upper end portion and the lower end portion of the marker.   
     
     
         11 . The antenna device according to  claim 8 , further comprising:
 a storage that stores multiple sets of phase data for respective elevation angles, the phase data indicating phases in which the transmission power signals are transmitted by the respective antenna elements to a power receiver that is at a position of the marker, the phases being adjusted such that the adjusted phases of the transmission power signals, from the antenna elements, received by the power receiver are matched,   wherein the storage stores the multiple sets of phase data that correspond to respective distances between the image acquiring device and the marker, and   wherein the control circuit is configured to
 retrieve, from the storage, the phase data in association with the distance in the third axis direction and the first elevation angle, and 
 control the phase adjuster based on the retrieved phase data. 
   
     
     
         12 . A feed system comprising:
 the antenna device according to  claim 8 ;   a radio wave generator configured to supply the transmission power signals to the multiple antenna elements;   a power receiver at a position of the marker; and   the marker attached to the power receiver,   wherein the marker is longer in a vertical direction than in a lateral direction.   
     
     
         13 . The feed system according to  claim 12 , wherein a middle portion of the marker includes a wide portion in the vertical direction. 
     
     
         14 . The feed system according to  claim 13 , wherein the wide portion is located at a middle position in the vertical direction. 
     
     
         15 . A feed device comprising:
 an array antenna including multiple antenna elements that are bidimensionally arranged along a first axis and a second axis;   a radio wave generator;   a phase adjuster provided between the array antenna and the radio wave generator, and configured to adjust phases of transmission power signals that are respectively supplied from the radio wave generator to the multiple antenna elements, with respect to a first axis direction;   an image acquiring device configured to acquire an image through a fisheye lens;   circuitry configured to:
 convert a first position of a marker that is included in the image, into a second position of polar coordinates on a first plane that includes the first axis and the second axis, the first position being used in the image acquiring device; 
 acquire, based on the second position, a first elevation angle of a projected position that is obtained by projecting the first position onto a second plane including the first axis and a third axis, the first elevation angle being relative to the third axis of the second plane; 
 estimate distances between the image acquiring device and the marker; and 
 control the phase adjuster based on the first elevation angle and an estimated distance in a third axis direction, 
   wherein the circuitry is configured to:
 estimate a distance between the image acquiring device and the marker in a first axis direction, based on
 coordinates of an upper end portion of the marker, the coordinates being determined based on a second elevation angle and an azimuth angle of the upper end portion of the marker included in the image, the second elevation angle being relative to the third axis, and the azimuth angle being relative to the first axis, 
 coordinates of a lower end portion of the marker, the coordinates of the lower end portion being determined based on a third elevation angle and an azimuth angle of the lower end portion of the marker included in the image, the third elevation angle being relative to the third axis, and the azimuth angle of the lower end portion being relative to the first axis, and 
 a length between the upper end portion and the lower end portion, 
 
 estimate the distance between the image acquiring device and the marker in the third axis direction, based on the first elevation angle and the estimated distance in the first axis direction. 
   
     
     
         16 . A feed method by a feed device including:
 an array antenna including multiple antenna elements that are bidimensionally arranged along a first axis and a second axis;   a radio wave generator;   a phase adjuster provided between the array antenna and the radio wave generator, and configured to adjust phases of transmission power signals that are respectively supplied from the radio wave generator to the multiple antenna elements, with respect to a first axis direction;   an image acquiring device configured to acquire an image through a fisheye lens;   circuitry configured to
 convert a first position of a marker that is included in the image, into a second position of polar coordinates on a first plane that includes the first axis and the second axis, the first position being used in the image acquiring device; and
 to acquire, based on the second position, a first elevation angle of a projected position that is obtained by projecting the first position onto a second plane including the first axis and a third axis, the first elevation angle being relative to the third axis of the second plane, the feed method comprising: 
 
   estimating a distance between the image acquiring device and the marker in the first axis direction, based on
 coordinates of an upper end portion of the marker, the coordinates being determined based on a second elevation angle and an azimuth angle of the upper end portion of the marker included in the image, the second elevation angle being relative to the third axis, and the azimuth angle being relative to the first axis, 
 coordinates of a lower end portion of the marker, the coordinates of the lower end portion being determined based on a third elevation angle and an azimuth angle of the lower end portion of the marker included in the image, the third elevation angle being relative to the third axis, and the azimuth angle of the lower end portion being relative to the first axis, and 
 a length between the upper end portion and the lower end portion; 
   estimating a distance between the image acquiring device and the marker in a third axis direction, based on the first elevation angle and the estimated distance in the first axis direction; and   controlling the phase adjuster based on the first elevation angle and an estimated distance in the third axis direction.